Yes, I agree. But, from what I've seen -- the FBI did drop the ball here, because the guy was certainly acting suspiciously AND was reported.
When a guy that has been investigated for terroristic threats and was given a pass because he was Islamic, and THEN is reported trying to buy body armor and a lot of ammo, I would think at least a yellow flag should have been thrown.
Gun ship owner had no name, no video, no license plate